Disk Replacement; Storeonce 4900 Backup Raid Configuration; Hot Spare Disks; Disk Bay Locations - HP StoreOnce 4900 Service And Maintenance Manual

9 Disk replacement

StoreOnce 4900 Backup RAID configuration

The HPE StoreOnce 4900 server unit has two disks only, which are used for the operating system
and filesystem. If one disk fails, the server unit will continue to operate but the failed disk should
be replaced immediately.
The HPE StoreOnce 4900 Backup system always requires one disk enclosure with base storage
of 11 disks for user data + 4 hot spare disks. These disks are configured in RAID 6 pools, such
that two disks per pool can be lost without loss of backup data. Up to five additional expansion
kits may be added to the disks in the first disk enclosure to increase the backup data capacity,
also RAID 6.
One further disk enclosure can be added to the system, and is connected to the second RAID
controller card. Up to five additional expansion kits may also be added to the disks in the second
disk enclosure to increase the backup data capacity, and the storage expansion model is the
same as for the first disk enclosure.
For instructions on how to connect additional storage by installing a StoreOnce 4900 Backup
44TB or 60TB capacity expansion kit, please see the printed documentation supplied with the
additional storage.

Hot spare disks

There are two hot spare disks in each drawer of the disk enclosure, bays 34 and 35. If a data
disk fails, the hot spare disk is automatically used until the failed disk is replaced. The disk is
only returned to its status of hot spare disk when the data is fully rebuilt on the replacement disk.
The hot spare disks maintain RAID 6 redundancy for the volumes within each drawer when a
drive has failed. However, it is important to replace failed or predictive failing disks as soon as
possible. If more than two disks fail in the same RAID volume, the system will fail and data will
be lost.

Disk bay locations

The following drawing identifies disk bay locations within a drawer.
Figure 10 Disk bay locations
1
2
3
4
5
6
7
NOTE: Disk bays 1 to 7 are at the front of the drawer.
28 Disk replacement
8 15
9 16
10 17
11 18
12 19
13 20
14 21
22 29
23 30
24 31
25 32
26 33
27 34
28 35